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Fingerstick

Capillary blood test

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In medicine, some blood tests are conducted on capillary blood obtained by fingerstick (or fingerprick) (or, for neonates, by an analogous heelprick). The site, free of surface arterial flow, where the blood is to be collected is sterilized with a topical germicide, and the skin pierced with a sterile lancet. After a droplet has formed, capillary blood is captured in a capillary tube (usually relying on surface tension) or on a membrane.

01Advantages

Capillary blood is easy to obtain especially for people with bad veins and infants. This method requires lower blood volumes which reduces the chance of anemia, it can be done from home and requires no training. It is less invasive and cheaper than traditional venous blood sampling. This method could improve the lives of patients who need regular check ups, have flaring diseases, or live remotely and have less access to doctors or phlebotomists.

02Disadvantages

Capillary blood is more prone to inconsistencies due to the lower blood volume, or differences in drawing capillary blood. Blood cells drawn from fingersticks have a tendency to undergo hemolysis, especially if the finger is "milked" to obtain more blood. When the finger is "milked", the blood dilutes and the quantities of metabolites or biomarkers will be incorrect. Further, regularly pricking the finger could cause scarring and occasionally leads to calcified nodules in infants.

03Uses

Tests commonly conducted on the capillary blood collected are:

Fingersticks are routine for adults, but are generally performed on children and the elderly only if a small amount of blood suffices for needed tests. Neonates are given heelpricks instead, as this is less likely to cause permanent damage.

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Sources and credits

This article is adapted from the Wikipedia article Fingerstick, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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